The present invention relates to quaternary ammonium compounds and formulations thereof useful as, for instance, cleaning compositions, antistatic compounds, fabric softeners, hair conditioners, skin conditioners, paper deinking and ink floatation agents, asphalt emulsion agents, corrosion inhibitor agents, ore floatation agents, pesticide emulsion agents, car drying aid sprays, drilling fluid additives, and the like.
Heretofore quaternary ammonium compounds and a very few dialkyl ammonium compounds ("conventional quats") have found widespread use in many applications. For example, a variety of conventional quats have been proposed for many uses, for example, in fabric softeners for home use or for industrial and institutional use. In general, such compounds exhibit properties which present some difficulty in the manufacture, formulation use, aesthetic properties, biodegradability, and environmental compatibility of these compositions. For example, many of the conventional compositions used for these functions, even if completely biodegradable with time, do not biodegrade as rapidly as could be desired and are thus not considered readily biodegradable. In addition, several of the commercial readily biodegradable softeners, conditioners, and debonders do not function as effectively as the conventional products that are less biodegradable. Thus, to maintain effective levels of performance, increased amounts of such less effective, more readily biodegradable products (such as softeners) must be employed and, as will be readily apparent, this factor decreases the cost-effectiveness of the product.
The relatively poor solubility of conventional quats also contributes to certain difficulties that will vary, depending on the application. For example, when such conventional quats are used in fabric softeners, their poor solubility inhibits the dispersibility of the fabric softener actives into water and the dispersibility of the formulated fabric softener product into the washing machine. In washing of textiles, the rinse softeners are often used in the last washing stage. In this way, coarsening of the fabric is lessened which otherwise could be realized upon drying. The feel of textiles treated in this way such as hand and bath towels as well as clothes and bed linens is pleasantly improved.
Cationic compounds are customarily used as rinse softeners, for example, quaternary ammonium compounds which can contain long-chain alkyl groups as well as ester groups or amide groups, such as are described in U.S. Pat. Nos. 3,349,043; 3,644,203; 3,946,115; 3,997,453; 4,073,735; and 4,119,545. These quaternary ammonium compounds are added to the rinse water by themselves or in mixtures with other cationic or neutral compounds in the form of aqueous dispersions.
In addition, quaternary ammonium compounds which contain ester linkages are frequently used, such as are described in EP-A-023910, U.S. Pat. Nos. 3,915,867; 4,137,180; and 4,830,771. Particularly widely used are ester compounds based on triethanolamine such as N-methyl, N,N-bis(.beta.-C.sub.14-18 -acyloxyethyl), N-.beta.-hydroxyethyl ammonium methylsulfate, which are available from Kao Corporation under tradename TETRANYL.RTM. AT 75, from Stepan Corporation under the tradename STEPANTEX.RTM. ZRH 90, and from Witco Surfactants GmbH under the tradename REWOQUAT.RTM. WE 18. While these cationic compounds exhibit effective softening when used in the last rinse stage, they exhibit some disadvantages during use. For example, one disadvantage is that a relatively large amount of softening agents is required to simultaneously obtain good rewettability and soft feel of textiles, although the softness is still unsatisfactory. Rewetting power or rewettability is generally taken to mean the absorption of moisture by the fiber. Inadequate rewetting power is, however, disadvantageous wherever relatively large amounts of moisture are to be absorbed from the surface of the skin, for example, in the case of hand or bath towels and in the case of underwear or bed linen. However, batch or continuous processes are known that can be used to prepare stable fabric softener dispersions using these products.
Thus, there remains a need for identification of new amine and ammonium derivatives, and particular quaternary derivatives, which are useful as fabric softeners and which are also biodegradable, highly effective in softening, debonding, conditioning, and the like, and yet avoid these problems upon manufacture, formulation and use. It is also desirable for the active agents used in hair and skin conditioners, textile softeners, and the like, to be readily biodegradable and to exhibit a satisfactorily high activity. Conventional products have to date not been able to exhibit both properties to a high degree, thus necessitating acceptance of reduced biodegradability or reduced activity. There is thus still a need for compounds exhibiting levels of activity as conditioners, and so on, as the case may be, which are comparable or superior to conventionally employed actives, such as conventional quats, while also exhibiting ready biodegradability.
As can be appreciated, the chemistry of fabric softeners, hair conditioners, skin conditioners, textile softeners, car wax sprays, and the like is challenging. Each of these applications presents its own complications, because the interactions between the various components of the compositions must be considered in addition to the individual chemistry of each component. For example, considering the fabric softening application, the detergent compounds with the widest range of cleaning properties are generally anionic (negatively charged) surfactants. Such anionic surfactants, for example, may include the alkylbenzene sulfonates, .alpha.-olefin sulfonates, and xylene sulfonates available from Witco Corporation under the WITCONATE.RTM. trademark. In contrast, as exemplified by the amine and ammonium compounds discussed above, fabric softening compounds are generally cationic (positively charged). Thus, when the anionic detergent ingredients and cationic softening ingredients are present in the same aqueous solution, they have a natural tendency to complex together or even precipitate out of solution. This complexation or precipitation reaction interferes with the performance of both the detergent compounds and the softening compounds and is therefore undesirable. It can be readily appreciated that this undesirable complexation or precipitation reaction may occur if both detergent and softener compounds are added together in a wash cycle; however, as North American washing machines typically rinse the clothes only once before fabric softener is added to the washload, even if the fabric softener is added during a rinse cycle (as is typically done), residual anionic detergent compounds (including builders) present in the fabric complexes with the cationic softener compounds.